The present invention relates generally to model railroads and more particularly to couplers for use in model railroads.
Model railroad couplers are well known. These devices, which are basically mechanical linkage type devices for coupling one model railroad car to another model railroad car in series, very often comprise a shank, a knuckle, a spring and a trip pin. The shank is shaped to define a joining element at one end for attaching the coupler to a unit of model railroad rolling stock. The other end of the shank is shaped to receive the knuckle. The knuckle is mounted on the shank for limited rotational movement. The spring is coupled to the knuckle and the shank is used to bias the knuckle to pivot into the closed position. The trip pin is used to remotely uncouple one coupler from another coupler to which it is attached.
In U.S. Pat. No. 5,785,192 to M. N. Dunham et al. there is disclosed a coupler of the type described above. The coupler includes a coupler shank, having a joining element at one end thereof and a coupler head at the other end thereof. A coupler-knuckle receiver is located within the coupler head and receives a coupler knuckle. The knuckle is provided with limited, rotational movement within the coupler head, through a predefined arc. The coupler head has a first knuckle stop located thereon which limits rotational movement of the coupler knuckle relative to the coupler head in a first direction of rotation. A second knuckle stop is located on one side of the coupler head adjacent to the shank. A knuckle limiter is located on the coupler knuckle. The second knuckle stop and the knuckle limiter are constructed and arranged to abut one another when the coupler knuckle is shifted to an open position, thereby stopping rotation of the coupler knuckle relative to the coupler head. A spring is carried on the second knuckle stop and the knuckle limiter extends therebetween, and is operable to urge the coupler knuckle to a closed position wherein the coupler knuckle abuts the first knuckle stop.
In U.S. Pat. No. 5,823,371 to H. L. Riley et al. there is disclosed another coupler of this type. The coupler includes a drawbar having first and second ends. The first end includes an aperture defined therethrough adapted for mounting in a coupler pocket on model railroad rolling stock. The second end includes a coupler head. A coupler knuckler is pivotably mounted to the coupler head by a magnetically actuated pivot post. A first coil spring alignment pin is located on the second end of the drawbar. A second coil spring alignment pin is located on the coupler knuckle. A coil spring is mounted between the coupler head and the coupler knuckle on the first and second coil spring alignment pins for resiliently urging the coupler knuckle to a coupled position. At least one of the first and second coil spring alignment pins includes a coil spring retainer which engages at least a portion of the coil spring to prevent the coil spring from becoming dislodged from the at least one or the first and second coil spring alignment pins.
In U.S. Pat. No. 5,662,229 to L. D. Edwards there is disclosed a model railroad coupler system which includes a draft gear box and a coupler. The coupler includes a coupler head and a coupler knuckle. An elongate coupler shank extends between the coupler head and a coupler mounting structure. The coupler mounting structure includes a mounting plate, which may have forwardly diverging sides thereto. Plural centering springs are fixed on each side of the coupler mounting plate such that when the coupler is centered, the centering springs make touching, non-flexed contact with the interior of the draft gear box and, when the coupler is pushed off-center, one of the centering springs makes flexed contact within an interior side of the draft box and the other centering spring does not make any contact with the other side of the draft box.
As can be appreciated, the couplers of the type described above are not entirely prototypical in that additional structure has been included to make the device functional. In particular, these devices have added a spring for biasing the knuckle to the closed position. The spring is located outside of the shank, is visible and is coupled to the knuckle. Such a spring is not found on prototypical couplers. Consequently, these couplers are not identical in appearance to prototypical couplers.
Other patents of interest are U.S. Pat. No. 2,658,629; U.S. Pat. No. 3,469,713; U.S. Pat. No. 3,564,766; U.S. Pat. No. 3,609,912; U.S. Pat. No. 3,659,725; U.S. Pat. No. 3,942,648; U.S. Pat. No. 5,316,158; U.S. Pat. No. 5,509,546; U.S. Pat. No. 5,746,336; U.S. Pat. No. 5,931,322; U.S. Pat. No. 6,189,713; and U.S. Pat. No. 6,308,845.
Accordingly, it is an object of this invention to provide a model railroad coupler which closely resembles prototypical couplers.